The present invention relates to a method of magnetic resonance imaging (=MRI) technology for reduction of motion related artifacts in 3D MR data acquisition with multiple segments. In particular, the invention pertains to a method of magnetic resonance (=MR) imaging for the acquisition of a three-dimensional (=3D) dataset of an object of investigation, where spatial encoding by three mutually orthogonal magnetic field gradients is performed such, that signal is readout under a read-gradient in one spatial direction and spatial encoding in the other two spatial directions is performed by applying phase encoding gradients in the other two spatial directions prior to signal acquisition and data acquisition is performed in a sequential manner such, that at each acquisition step signal is acquired under said readout gradient, but with different combinations of the two phase encoding gradients.
Such method is known from reference [3] (Busse et al.).
The scan time of 3D MRI is long and is prone to artifacts caused by patient motion. Recently developed k-space random sampling techniques (also known as Compressed Sensing, see reference [2]) support the image reconstruction using randomly sampled k-space datasets. Recently developed view reordering (see reference [3]) supports the flexible filling of 3D gridded k-space with multiple segments. In a recently developed method for dynamic MR angiography progressive filling of k-space is performed to allow for a trade-off of temporal resolution and image sharpness (see reference [4]). Navigator echo (see reference [5]) is an easy and reliable way for motion detection, which was already used to monitor the respiration motion, swallowing cased motion etc.
To the present moment no method for 3D structural imaging is known which is capable of being interrupted due to the patient's or subject's motion, where it would be possible to reconstruct high quality anatomic images with only partial data and where the quality of the complete data set would not be compromised to allow for the flexibility of interrupting the scan.
An object of the present invention is to propose a method for reduction of motion related artifacts in 3D MR data acquisition, where data are acquired under a readout gradient for spatial encoding in the first spatial dimension (referred to as K1). Data in the 2nd and 3rd spatial dimension are spatially encoded according using two mutually orthogonal phase encoding gradients (referred to as K2 and K3). The invention applies to any MR sequence suitable for this spatial encoding strategy. This includes 3D-acquisition with steady state techniques like gradient echoes, contrast prepared gradient echo techniques like MDEFT and MPRAGE as well as 3D-multiecho-techniques (3D-TSE, SPACE).